/lib/partman/visual.d/25method is in ubiquity 2.21.63.
This file is owned by root:root, with mode 0o755.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 | #!/bin/sh
cd $1
num=$2
id=$3
size=$4
type=$5
fs=$6
path=$7
name=$8
if [ -f $id/method ]; then
if [ -f $id/format ]; then
if [ -f $id/detected_filesystem ]; then
printf "F"
else
printf "f"
fi
else
printf "K"
fi
fi
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